The field of the present invention relates to laser sources. In particular, a laser source for a passive optical network is disclosed herein.
In a typical passive optical network (PON), multiple network termini 102 are connected to a single network node 104 via an optical splitter network 106 (FIG. 1). Downstream optical signals are routed from the network node 104 through the splitter network 106 and reach all of the network termini 102, regardless of the intended target terminus of the signal. Upstream signals originating at a network terminus 102 are transmitted through the splitter network 106 to the network node 104. If upstream optical signals are transmitted from two or more network termini 102 simultaneously, those signals might interfere with one another upon reaching the network node 104, or further upstream from the network node.
Upstream optical signals are typically generated at a network terminus in response to radio-frequency (RF) electrical signals carrying desired information. The upstream optical signal typically comprises some DC optical power level (also referred to as a DC optical set point), with the information carried by optical modulation about the set point. The modulation of the optical signal is typically driven by the corresponding RF electrical signal. The source of the optical signal is typically a laser source or other coherent optical source.
It may be desirable to provide a laser source for use in a passive optical network that reduces the likelihood or severity of interference between simultaneously transmitted upstream optical signals.